Hydrogenated olefin sulfonate detergent bars

ABSTRACT

Non-soap hydrogenated olefin sulfonate detergent toilet bars having improved slough loss and wear rate characteristics comprise a mixture of the sodium and magnesium salts of hydrogenated olefin sulfonates containing from 10 to 25 carbon atoms in a ratio of the sodium to the magnesium salt of 2:1 to 1: 20 and a plasticizing amount of water.

United States Patent Woo I54] HYDROGENATED OLEFIN SULFONATE DETERGENTBARS 3,506,580 3/1970 Rubinfcld eta]. ..252/138 WEAR RATE(GRAMS/WASHING) 1 June 27, 1972 3,523,089 8/1970 Garrett ..252/16l3,346,629 10/1967 Broussalian ..260/513 FOREIGN PATENTS OR APPLICATIONSFrance France ..252/DIG. 16

Primary Examiner-Leon D. Rosdol Assistant Examiner-P. E. WillisAttorney-A. L. Snow, F. E. Johnston and John Stoner, Jr.

[57] ABSTRACT Non-soap hydrogenated olefin sulfonate detergent toiletbars having improved slough loss and wear rate characteristics comprisea mixture of the sodium and magnesium salts of hydrogenated olefinsulfonates containing from 10 to 25 carbon atoms in a ratio of thesodium to the magnesium salt of 2:1 to 1:20 and a plasticizing amount ofwater.

4 Claims, 1 Drawing Figure .o I I I 1* I I 100 75 25 o NG 7, BY WEIGHT0F METAL SULFONATE PATENTEDJ NZ? I912 3.673.122

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If .4 [If .0 I 'l l l I o 25 so 75 100 1 n 1 l 100 75 so 25 o' Na 7, BYWEIGHT OF METAL SULFONATE INVENTOR AR LOK woo BYM g ATTORNEY g8I'IYDROGENATED OLEFIN SULFONATE DETERGENT BARS I BACKGROUND OF THEINVENTION The present invention is concerned with the field of syntheticnon-soap detergent bars and, more particularly, with the preparation ofbars or cakes for toilet or bath use from improved mixtures ofhydrogenated olefin sulfonates.

Although synthetic detergents have largely replaced soaps for mosthousehold laundering and dishwashing uses, they have found littleacceptance in the household toilet bar area. Although the detergentliterature is replete with examples of synthetic detergent bars andsynthetic detergent-soap combination bars, the toilet bar marketcontinues to be dominated by soap bars. The combination bars have hadappreciable ac-.

ceptance but they exhibit the high pH characteristic of soap bars. Atthe present time, it appears that less than 1 percent of the bar marketis satisfied by all synthetic detergent bars.

As disclosed in copending application, U.S. Ser. No. 748,188, filed July29, 1968, it has been discovered that superior non-soap syntheticdetergent bars can be formed employing hydrogenated linear olefinsulfonates as the major active detergent component. In particular,mixtures of straightchain hydrogenated olefin sulfonates containing from10 to 24 carbon atoms constitute a superior detergent component fornon-soap detergent toilet bars. Although these hydrogenated olefinsulfonate bars comprise a significant advance over the non-soapdetergent bars of the prior art, they are not as low in slough loss andwear rate as is desirable.

DESCRIPTION OF THE INVENTION It has now been discovered that superiornon-soap synthetic detergent bars low in slough loss and wear rate canbe formed employing improved hydrogenated linear olefin sulfonates asthe major active detergent component. In particular, mixtures of sodiumand magnesium salts of straight-chain hydrogenated olefin sulfonatescontaining from 10 to 24 carbon atoms constitute a superior detergentcomponent for non-soap detergent toilet bars. In general, when the ratioof sodium to magnesium salts is in a weight ratio of from 2:1 to 1:20,excellent slough loss and wear rate characteristics are exhibited withlittle or no appreciable efiect on the other outstanding properties ofhydrogenated olefin sulfonate detergent bars. Preferably, the ratio ofsodium to magnesium salts is from 1:2 to 1:9.

v The term olefin sulfonates" as used in the present invention, definesthe complex mixture obtained by the S sulfonation of straight-chainolefins containing to 24 carbon atoms and subsequent neutralization andhydrolysis of the sulfonation reaction product. This complex mixturecontains hydroxyalkane sulfonates and alkene sulfonates, as its majorcomponents, and a lesser proportion of disulfonated product.

While the general nature and the major components of the complex mixtureis known, the specific identity and the relative proportions of thevarious hydroxy sulfonate and disulfonate radicals and double bondlocations are unknown. Accordingly, a determination of the entirechemical makeup is exceedingly difficult and has not heretofore beensuccessfully accomplished. The mixture is best defined by the processused for producing it.

Optimum detergent bar properties are exhibited by the compositionobtained by hydrogenating an olefin sulfonate product which containsfrom about 25 to 75 percent by weight alkene sulfonates, from about 25to 65 percent by weight hydroxyalkane sulfonates, and not more thanweight percent disulfonates. These optimum compositions are obtained bySO -air sulfonation of C -C straight-chain olefins with SO :air volumeratio of about 150-100 and an SO :olefin mole ratio of 1.05-1.2521, andneutralization and hydrolysis of the sulfonation reaction product attemperatures of 145250 C. using one equivalent of base per mole of S0consumed in the sulfonation step.

In addition to the straight-chain a-olefins from wax cracking, suitableolefin starting materials include straightchain ot-olefins produced byZiegler polymerization of ethylene, or internal straight-chain olefinsprepared by catalytic dehydrogenation of normal paraflins or bychlorinationdehydrochlorination of normal parafiins. The olefins maycontain from 10 to 24 carbon atoms, usually 13 to 22 carbon atoms,preferably 14 to 20, and more preferably 15 to 18 carbon atoms permolecule. Olefin mixture should have an average molecular weight of atleast about 200.

The amount of S0,, utilized in the sulfonation reaction may be variedbut is usually within the range of 0.95 to 1.35 moles of S0 per mole ofolefin and, preferably, in the range 1.05-1 .25: 1. Greater formation ofdisulfonated products is observed at higher SO :o1efin ratios.Disulfonation may be reduced by carrying the sulfonation reaction onlyto partial conversion of the olefin; for example, by using sO zolefinratios of less than 1 and removing the unreacted olefins by a deoilingprocess. The unreacted olefins may be removed by extracting the reactionproduct with a hydrocarbon such as pentane.

In order to obtain a product of good color, the 80,, employed in thesulfonation reaction is generally mixed with an inert diluent or with amodifying agent. Inert diluents which are satisfactory for this purposeinclude air, nitrogen, S0 dichloromethane, etc. The volume ratio of 50;,to diluent is usually within the range of 1:100 to 1:1.

The reaction product from the sulfonation step step may be neutralizedwith aqueous basic solutions containing the sodium or magnesiumhydroxides, carbonates or oxides. In the preferred method, suflicientneutralizing solution may be added to provide for neutralization of thesulfonic acids formed by sultone hydrolysis. Generally, one equivalentof base for each mole of S0 consumed in the sulfonation reaction isadded to the sulfonation reaction product. The proportion ofhydroxyalkane sulfonates to alkene sulfonates in the hydrolyzedneutralized product may be varied somewhat by the manner in whichneutralization and hydrolysis are carried out. Thus, reduced amounts ofhydroxyalkane sulfonates are obtained by carrying out the neutralizationand hydrolysis at temperatures in the range of 145-200 C. while higheryields of hydroxy sulfonate are favored by carrying out theneutralization and hydrolysis at temperatures below 100 C. Suitablehydrolysis temperatures range from about l00-200 C. The followingexamples describe the preparation of the precursor olefin sulfonatessuitable for preparing hydrogenated olefin sulfonates within the scopeof the present invention.

Example 1 Preparation of Sodium Olefin Sulfonates The reactor used forthis sulfonation consisted of a continuous falling film-type unit in theform of a vertical waterjacketed tube. Both the olefin and the SO -airmixture were introduced at the top of the reactor and flowedconcurrently down the reactor. At the bottom, the sulfonated product wasseparated from the air stream.

The feed was a straight-chain l-olefin blend produced by cracking highlyparaffinic wax and having the following composition by weight: 1 percenttetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percentheptadecene, 14 percent octadecene and 1 percent nonadecene. Thismaterial was charged to the top of the above-described reactor at a rateof 306 pounds/hour. At the same time 124.2 pounds/hour of S0 dilutedwith air to 3 percent by volume concentration of was introduced into thetop of the reactor. The reactor was cooled with water to maintain thetemperature of the effluent product within the range of 43-46 C. Theaverage residence time of the reactants in the reactor was less than 2minutes.

After passing out of the reactor the sulfonated product was mixed with612 pounds/hour of 11.2 percent aqueous caustic and heated to l45-150 C.in a tubular reactor at an average residence time of 30 minutes. Thisstep neutralized the sulfonic acids contained in the sulfonationreaction product, hydrolyzed the sultones to hydroxy sulfonic acids andto alkene sulfonic acids and neutralized these sulfonic acids. Olefinsulfonates were producedat the rate of 463 pounds per hour as an aqueoussolution having a 45 percent by weight solids content and a pH of 10.8.

A portion ofthis product was analyzed and shown to be made up of thesodium salts of alkene sulfonic acids, hydroxy alkane sulfonic acids,and disulfonic acids. These three major components were present in aweight ratio of about 50:35: 15. Example 2 Preparation of Magnesium C,.,C a-Olefin Sulfonate The reactor usedfor this sulfonation consisted ofa small laboratory continuous falling film-type unit similar to the onedescribed in Example 1 above.

The feed was a straight-chain l-olefin blend produced by cracking highlyparaffinic wax and having the following composition by weight: 1 percenttetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percentheptadecene, 14 percent octadecene and 1 percent nonadecene. Thismaterial was charged to the top of the reactor at a rate of 267grams/hour. At the same time, 112 grams/hour of S0,, diluted withnitrogen to 2 percent by volume concentration of 80 was introduced intothe top of the reactor. The reactor was cooled with water to maintainthe temperature of the effluent product within the range of 43-46 C. Theaverage residence time of the reactants in the reactor was less than 2minutes.

After passing out of the reactor the sulfonated product was mixed with772 grams/hour of 4.2 percent magnesium oxide slurry and heated tol45l55 C. in a tubular reactor at an average residence time of 30minutes. This step neutralized the sulfonic acids contained in thesulfonation reaction product, hydrolyzed the sultones to hydroxysulfonic acids and neutralized the hydroxy sulfonic acids. The magnesiumolefin sulfonate produced still contained trace amount of magnesiumoxide which was removed by filtration. The product was brought to aboutpH 6.5 with H SO and diluted-to an aqueous solution having a 28.6percent by weight solid content. Example 3 Preparation of HydrogenatedSodium Olefin Sulfonates The apparatus for this hydrogenation consistedof a 1-liter Magne-Drive autoclave equipped with an accumulator, aconstant pressure regulator, and a temperature recording means. Theproduct of Example 1 was diluted with water to a 26 percent solidsconcentration and was filtered to remove a trace amount of insolublematerial. The pH was adjusted to a value of 6.5-7.5 by neutralizing theslight excess of NaOH used in the neutralization and hydrolysis stepwith H 80 100 parts of 30 percent hydrogen peroxide was then added to3,850 parts of the filtered 26 percent solution in an open glass vessel.This mixture was heated to 80 C. and stirred for 1 hour at thistemperature, after which time no hydrogen peroxide remained. Aftercooling this solution to room temperature, 650 g. of it was charged tothe previously described autoclave, along with 8.5 g. of Raney nickel.The system was purged with nitrogen and then with hydrogen. it was thenpressured with hydrogen to 50 psig. The autoclave was warmed to 100 C.at which temperature hydrogen was again introduced to bring the pressureup to 100 psig. The hydrogen pressure was maintained constant at 100psig. throughout the run. After 1% hours of stirring at this temperatureand pressure, and at which time there was no additional hydrogen uptake,the solution was cooled to about 70 C., filtered, and then allowed tocool. After cooling the final product was drum dried. Example 4Preparation of Hydrogenated Magnesium Olefin Sulfonates The product ofExample 2 was treated with hydrogen peroxide as in Example 3. Theresidual hydrogen peroxide was decomposed over platinum. The treatedproduct was then hydrogenated with Raney nickel as in Example 3. Thefinal product was drum dried.

The alkene sulfonates need not be completely hydrogenated. Partialhydrogenation of the olefin sulfonate to the extent that at least 50percent of the alkene sulfonate is converted to alkane sulfonate yieldsa hydrogenated olefin sulfonate suitable for use in producing highquality non-soap detergent bars. Partial hydrogenation may beaccomplished by proceeding as in Example 3, but discontinuing thehydrogenation reaction before hydrogen uptake ceases. Partialhydrogenation can also be carried out by subjecting the olefin sulfonateto hydrogenation after neutralization but prior to hydrolysis.

Example 5 Preparation of Bars The drum-dried magnesium and/or sodiumhydrogenated olefin sulfonates, approximately 200 g., were well mixed inthe desired ratios. Enough water was gradually added during milling suchthat the hydrogenated olefin sulfonate could be milled into ribbons ofhomogeneous composition. It is then formed into bars by molding into aconventional soap bar mold. The bars formed in this way were about 2%inches by 1% inches by 158 inch in size. These bars were aged byexposure to air in a room at ambient temperature and humidity for oneweek. The bars then weighed 26-27 g. In general, from about 2 to 15percent by weight water is sufficient to produce satisfactory bars.

Hydrogenated a-olefin sulfonate bars of varying ratios of sodium andmagnesium cations were tested for slough loss and wear rate and theresults are summarized in Table l. The slough loss test was run byplacing the bar in a 3% inch l.D. Petri dish containing 30 ml. of waterhaving 50 ppm hardness. After 18 hours, the bar was removed and anyloose gel was rubbed off. Then the bar was allowed to dry for 24 hoursand weighed. The loss in weight percent in grams of the bar is reportedas slough loss.

An important property of detergent bars is their solution rate underactual washing conditions. A convenient method of measuring thesolubility characteristics of a detergent bar is by deten'nining itsloss in weight in grams per handwashing. This value is referred to asthe bar wear rate. The values are obtained by averaging the weight lossfrom a number of handwashings by different individuals using tap waterat temperatures of about 1 10 F.

TABLE I Wear Rate and Slough Loss of Sodium-Magnesium HydrogenatedOlefin Sulfonate Bars Unhydrogenate'd a-olefin sulfonate as activeingredient.

All of the above examples were prepared by formulating a mixture of thecorrect amount of the sodium hydrogenated olefin sulfonates of Example 3and the magnesium hydrogenated olefin sulfonates of Example 4.

While completely satisfactory bars can be prepared from hydrogenatedolefin sulfonates as shown above, the feel and appearance of the barsmay be improved by incorporation of conventional emollients,superfatting agents, opacifiers, fillers, perfumes, dyes, and the like.These additives may constitute up to about 40 percent by weight of thefinished bar. Representative conventional additives are the polyethyleneglycols, C, C fatty alcohols, stearic acid, mineral oil, fatty acidamides, mixed fatty acid alkanolamine compounds,lauric-isopropanolamide, polyethylene glycol monostearates, and glycerolmonostearate.

In addition, it may be desirable to have incorporated within thenon-soap synthetic bar other detergent-active materials compatible withthe hydrogenated olefin sulfonates in an amount of from 0 to 25 percentby weight of the hydrogenated olefin sulfonates. Such detergent-activeswould include straight-chain alkylbenzene sulfonates, straight-chainprimary and secondary alkyl sulfates, polyoxyethylene alkylphenolsulfates, acylisothionates, alkyl glyceryl ether sulfonates, andsulfated fatty acid monoglycerides.

DESCRIPTION OF DRAWING The drawing graphically illustrates the effectdisclosed by the data in Table l of the variation of magnesium andsodium salt concentration on the wear rate of the detergent bars. Inparticular, the graph illustrates the improved characteristics of thedetergent bars containing a sodium to magnesium salt concentration ratioof from 2:1 to 1:20, and preferably from 1:2 to 1:9.

As will be evident to those skilled in the art, various modifications ofthe present products can be made or followed, in the light of theforegoing disclosure and discussion without departing from the spirit orscope of the disclosure or the scope of the following claims.

1 claim:

1. A non-soap detergent bar consisting essentially of A. a mixture ofsodium and magnesium salts of hydrogenated olefin sulfonates obtained byl. sulfonating straight-chain olefins containing from to 24 carbon atomswith diluted S0; at an sO zolefin mole ratio of 0.95 to 1.25,

2. neutralizing the product of (1) with at least one equivalent of baseper mol of S0 consumed in (l) and hydrolyzing the product of (1) at atemperature of between and 200 C. and 3. hydrogenating from 50 to 100percent of the unsaturated carbon-carbon double bonds in the product of(2), wherein the ratio of the sodium to magnesium salts is from about1:2 to 1:9, and

B. from about 2 to 15 percent by weight of water based on thehydrogenated olefin sulfonate content of the bar.

2. A non-soap detergent bar as in claim 1 wherein the hydrogenatedolefin sulfonates are hydrogenated a-olefin sulfonates.

3. A non-soap detergent bar as in claim 2 wherein the hydrogenatedolefin sulfonates contain from 14-20 carbon atoms.

4. A non-soap detergent bar as in claim 3 wherein the hydrogenatedolefin sulfonates contain from about 25-60 weight percent hydroxyalkanesulfonates and less than 20 weight percent of disulfonates.

2. neutralizing the product of (1) with at least one equivalent of baseper mol of SO3 consumed in (1) and hydrolyzing the product of (1) at atemperature of between 100* and 200* C., and
 2. A non-soap detergent baras in claim 1 wherein the hydrogenated olefin sulfonates arehydrogenated Alpha -olefin sulfonates.
 3. A non-soap detergent bar as inclaim 2 wherein the hydrogenated olefin sulfonates contain from 14-20carbon atoms.
 3. hydrogenating from 50 to 100 peRcent of the unsaturatedcarbon-carbon double bonds in the product of (2), wherein the ratio ofthe sodium to magnesium salts is from about 1:2 to 1:9, and B. fromabout 2 to 15 percent by weight of water based on the hydrogenatedolefin sulfonate content of the bar.
 4. A non-soap detergent bar as inclaim 3 wherein the hydrogenated olefin sulfonates contain from about25-60 weight percent hydroxyalkane sulfonates and less than 20 weightpercent of disulfonates.